This product has no function to fix the width of the grip in the middle, and when not in use both arms are fully closed with standby. Therefore even if you spread one arm with a smartphone, it will not fit inside the remaining arm if it is the width of iPhone 6 (about 70 mm). So, wearing a smartphone does not go with one hand with one hand, you need to work with both hands (two actions spreading the other arm separately). The iPhone 6 fits into the final opening width, but the operability at the time of installation is the worst. It is disappointing because price is sufficiently inexpensive, but regrettable mismatch with purpose of use was disappointing.